Auto vs 2H Settings...

Coastalman · November 7, 2016

When I bought my truck a few months ago (new) from the dealer, the 4wd switch was in the auto position. Well I now have 10K miles on my truck and was just told by a friend it's not supposed to be in the "auto" position all the time. does anyone have any info on this? & have several other buddies that have 16s and they were all in auto as well when purchased. Any insight on this would be great!

Silverado Steve · November 7, 2016

Topic has been covered to death.....let the shit storm ensue.

When I bought my truck a few months ago (new) from the dealer, the 4wd switch was in the auto position. Well I now have 10K miles on my truck and was just told by a friend it's not supposed to be in the "auto" position all the time. does anyone have any info on this? & have several other buddies that have 16s and they were all in auto as well when purchased. Any insight on this would be great!

SouthernSilveradoGuy85 · November 7, 2016

This is going to start another auto 4 in the rain debate. Personally it's not needed in the rain. In the manual it even said it's for inconsistent ground. Which is if parts of the road is snow/slush/ice and the other parts are dry or wet. Auto 4 is for the snow/slush and ice parts where you don't need 4hi the whole time, just parts of the road that has winter weather on it. So outside of winter weather 4hi isn't needed so put it in 2hi for normal driving. Ive driven when it pouring down where you couldn't see 10 feet in front of me and had 0 problems. Also I used to have an '86 C10 2wd and a '98 Z71 that didn't have the auto 4 feature and well I miraculously made it home every time in the rain in those. I don't think 4hi helps with anything in the rain. It would be like putting it in 4lo for a 2" deep 1' long mud puddle. The only time I can even understand having it in 4 auto with rain is in flooded areas that could lift the weight of the truck up a little which honestly in the situation you shouldn't be driving in flooded waters that are deep enough to lift a full size truck up a little to lighten the traction on the tires.

But hey, it's your truck so do what you want. You think you might need 4 auto in the rain then be my guest. Not sure if you're used to 4x4 systems on trucks and SUVs, but 4hi isn't the same as AWD.

Imcrazy · November 7, 2016

It's not how the system was designed to be used plus you waste a lot of fuel keeping it in auto all the time.

I rarely use anything but 2high on my truck on the paved road. When it snows if there is snow on the road I will toss it in auto or 4 hi, depends on how much and how consistent the snow cover is. In the rain, once or twice in really bad water cover roads I have put it in 4 high, I'm talking a lot of rain on the road. Really if it didn't snow and I didn't intend to take my truck off road I wouldn't bother even having a 4x4....

Knotsure · November 7, 2016

It will not harm the truck to drive in the auto setting. Everyone has there own preference with this one though. I personally love the auto 4 in the rain. I don't see much mpg difference in my experience and I do feel a difference from a stop and making turns when accelerating. You have to decide for yourself. I say enjoy whenever you want[emoji1360]

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Nathan79 · November 7, 2016

Read your owners manual. No damage to run in auto 4wd all the time but not needed and may burn more fuel.

kstruckcountry · November 7, 2016

Read your owners manual. No damage to run in auto 4wd all the time but not needed and may burn more fuel.

This here. No harm in it, but there's not really any reason to keep it on all the time.

truckguy82 · November 7, 2016

When I bought my truck a few months ago (new) from the dealer, the 4wd switch was in the auto position. Well I now have 10K miles on my truck and was just told by a friend it's not supposed to be in the "auto" position all the time. does anyone have any info on this? & have several other buddies that have 16s and they were all in auto as well when purchased. Any insight on this would be great!

It's not, turn it to 2wd

As someone who advocates using auto whenever it rains, leaving it on 24/7 is probably not something I would do.

There is noticable drivetrain resistance in auto, not a doubt in my mind it's causing a 5-10% increase in fuel consumption when in the auto position. I switch it on and off frequently.

Good to know that you put 10k miles on it in auto and had no issues. That's a lot

powerhaulic · November 7, 2016

2wd here as well

But I sure do miss the true AWD my '11 Denali had, worked perfectly

Really don't understand why GM did away with that system, had it in my '08 Savana van before that

Sean Neilan · November 7, 2016

Maybe it's cause I spent my late teeenage years and early 20's driving a 2wd manual S10 in nw Jersey winters in a town that doesn't plow, but unless there's several inches of snow on the road or I'm trying to go uphill I almost never use 4wd on the road. Really the only time I use it is when I'm driving on the beach. (And if you are using 4wd in the snow, just remember it helps you go, not stop)

truckguy82 · November 7, 2016

2wd here as well

But I sure do miss the true AWD my '11 Denali had, worked perfectly

Really don't understand why GM did away with that system, had it in my '08 Savana van before that

Why do you miss it?

The current truck is not much different from awd when in auto.

I like it a lot more than awd as you can turn it off when you want, and it also has a transfer case if you ever need to use 4low

It's like all the benefits of awd, 4wd, and 2wd wrapped up into one system.

powerhaulic · November 7, 2016

Why do you miss it?

The current truck is not much different from awd when in auto.

I like it a lot more than awd as you can turn it off when you want, and it also has a transfer case if you ever need to use 4low

It's like all the benefits of awd, 4wd, and 2wd wrapped up into one system.

Just plain seamless operation, with no fuel mileage penalty. Would have done it again if offered.

But I am extremely happy with my '17 Sierra

TxTruckMan · November 7, 2016

No point in using AUTO all the time - only when conditions necessitate it. It will impact your mileage about 10-20%. I only use it when raining to keep from spinning on turns and lights. It's great in slippery/rainy situations when you don't want to drive like a 90 year old lady.

kstruckcountry · November 7, 2016

Just plain seamless operation, with no fuel mileage penalty. Would have done it again if offered.

But I am extremely happy with my '17 Sierra

The old AWD system did cause a bit of a mpg hit, more than a traditional 4x4 system. Front axle engaged all the time. The mileage drop of the Auto system is noticeable, but since it can be put in 2hi when not needed, it's better from an mpg standpoint.

I've driven the AWD system though, and seamless is definitely the word for it. Awesome grip.

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sk · November 7, 2016

As others have said - there is no harm in leaving it in AUTO. The system will only send power to the wheels that spin so you won't damage the drivetrain on dry pavement like you will with 4High or 4Low.

That being said, there is also no harm in switching between 2H and AUTO as needed. Like some others said I leave it in 2H for most driving but on rainy days when I don't have much weight in the bed I leave it in AUTO for better traction especially when pulling out from a stop.

Also - it's in the Owners Manual.